It is known to generate acetylene from calcium carbide by the hydrolysis of the calcium carbide at elevated temperatures. Care must be taken to avoid introducing free oxygen into the hydrolysis reaction, so commercial acetylene generators use an inert gas, such as nitrogen, to purge the calcium carbide mixture of air before introducing the calcium carbide to the reaction vessel. After the calcium carbide mixture is purged of air in a purge hopper, the calcium carbide and nitrogen are transferred to a generator where they are mixed with water at an elevated temperature to generate acetylene. The transfer of calcium carbide and nitrogen to the reaction vessel results in the simultaneous transfer of some acetylene gas back into the purge hopper. In prior art acetylene generation methods, this acetylene is vented to the atmosphere during a post-transfer purge step to prepare the purge bin for a subsequent batch of calcium carbide.
A need currently exists for a system and method for recovering at least some of the acetylene that would otherwise be lost to the atmosphere during the post-generation purge. The present invention addresses that need.